Conservativity of three-dimensional structures of α-, β- and γ-interferons

Abstract

Using the method of estimation of α-helical and β-folded types of secondary structure from amino acid composition, it has been established that interferon-γ (IFN-γ) contains about 50–70% of α-helical and no more than 10–20% of β-structure. The same result was obtained using empirical and stereochemical rules for the prediction of protein secondary structure from amino acid sequence. Packing of α-helical segments of IFN-γ into 1 of the 2 three-dimensional structures previously suggested for IFN-α and IFN-β, allowed to detect high conservativity of the hydrophobic core of the proteins compared. On this basis a tentative conclusion has been drawn that all interferons have, in general features, a similar globular α-helical conformation.